Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=false, and the description is consistent with them by stressing it 'opens nothing by itself.' Beyond the annotations it adds genuinely useful context: the return format is a step-by-step walkthrough, and execution is delegated to browser tools. The API/pricing paragraph adds background but little behavioral clarity.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The first two sentences are tight and front-load the essential fact that this only returns instructions. The closing sentence about Fiken's REST API v2, its coverage, the check date, and the 99 NOK/month pricing is tangential to selecting or invoking this tool and dilutes the message.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no parameters, no output schema, and full annotation coverage, the description supplies what an agent needs: what the tool returns, what it does not do, and which sibling tools carry out the action. Only the extraneous API-pricing passage detracts, and no critical calling information is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters and the schema is trivially empty with no additionalProperties, so there is nothing for the description to disambiguate. Baseline for a parameterless tool applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific action and resource (add a contact in Fiken) and then immediately clarifies the actual behavior: it returns step-by-step instructions (screens, buttons, fields) rather than performing the write. That reframing is what lets an agent distinguish it from cotlet_browser_* tools, though the opening sentence initially reads like a mutation and requires the second sentence to correct it.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It states the follow-up path explicitly: this tool produces the how-to, and the actual execution happens via cotlet_browser_* in the user's Fiken Cloud Browser. That is clear when-to-use and what-to-use-next guidance. It stops short of naming when to skip this tool entirely (e.g., if the user already knows the steps), but the sequencing is unambiguous.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.